1. Field of the Invention
This invention relates to a restrictor device which in use can selectively restrict the degree of movement of a closure which is movably mounted with a fixed frame.
2. Discussion of the Background
There are known hardware fittings which can be mounted between a fixture such as a window or door frame and closure such as a window or door such that the extent of movement of the window or door relative to the frame can be limited. An example of such a fitting is that sold under the Securistay trade mark and which is described and claimed in our New Zealand Patent Specification 188689. The Securistay fitting provides an effective means of limiting the opening of a window yet readily permits, once the latch arm has been released, the window to be opened wider for say cleaning purposes. The latch arm automatically re-engages when the window is shut thereby limiting the extent to which the window can be re-opened. The arm can also be "locked" so that it can only be unlatched by authorized persons.
In use the Securistay product is not accessible from the outside of a window, however, it is mounted on the external surfaces of the interior of the window sash and frame thus is always visible. Being a utilitarian item of hardware it can distract from the aesthetics of the window. Also it has been found that in some situations such as in hotels etc. the device is often damaged by those endeavoring to open the window beyond its normal limited extent of opening. Such damage is normally caused by leverage or percussive forces and while these forces are not able to be rendered by someone located on the outside of the window (even when it is open to the limited extent allowed by the fitting) they can be readily applied to the fitting by a person inside the building. Such damage is often of such extent that the fitting becomes useless for the purpose for it was designed and in high rise applications a dangerous situation can arise whereby the extent of opening of the window can become unrestricted. As a result a person could fall through a window which has either been physically opened or sucked open in say high wind conditions.